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<div class="section" id="equal">
<h1><a class="toc-backref" href="./querying-algorithms.html#id1484">equal</a></h1>
<div class="section" id="id607">
<h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3>
<pre class="literal-block">
template&lt;
      typename Seq1
    , typename Seq2
    , typename Pred = is_same&lt;<a href="./placeholders.html" class="identifier">_1</a>,<a href="./placeholders.html" class="identifier">_2</a>&gt;
    &gt;
struct <a href="./equal.html" class="identifier">equal</a>
{
    typedef <em>unspecified</em> type;
};
</pre>
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<div class="section" id="id608">
<h3><a class="subsection-title" href="#description" name="description">Description</a></h3>
<p>Returns a true-valued <a class="reference internal" href="./integral-constant.html">Integral Constant</a> if the two sequences <tt class="literal"><span class="pre">Seq1</span></tt>
and <tt class="literal"><span class="pre">Seq2</span></tt> are identical when compared element-by-element.</p>
</div>
<div class="section" id="id609">
<h3><a class="subsection-title" href="#header" name="header">Header</a></h3>
<pre class="literal-block">
#include &lt;<a href="../../../../boost/mpl/equal.hpp" class="header">boost/mpl/equal.hpp</a>&gt;
</pre>
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<div class="section" id="id610">
<h3><a class="subsection-title" href="#parameters" name="parameters">Parameters</a></h3>
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<tr><th class="head">Parameter</th>
<th class="head">Requirement</th>
<th class="head">Description</th>
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<tr><td><tt class="literal"><span class="pre">Seq1</span></tt>, <tt class="literal"><span class="pre">Seq2</span></tt></td>
<td><a class="reference internal" href="./forward-sequence.html">Forward Sequence</a></td>
<td>Sequences to compare.</td>
</tr>
<tr><td><tt class="literal"><span class="pre">Pred</span></tt></td>
<td>Binary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a></td>
<td>A comparison criterion.</td>
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<div class="section" id="id611">
<h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3>
<p>For any <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a>s <tt class="literal"><span class="pre">s1</span></tt> and <tt class="literal"><span class="pre">s2</span></tt> and a binary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a> <tt class="literal"><span class="pre">pred</span></tt>:</p>
<pre class="literal-block">
typedef <a href="./equal.html" class="identifier">equal</a>&lt;s1,s2,pred&gt;::type c;
</pre>
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<tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><a class="reference internal" href="./integral-constant.html">Integral Constant</a></p>
</td>
</tr>
<tr class="field"><th class="field-name">Semantics:</th><td class="field-body"><p class="first"><tt class="literal"><span class="pre">c::value</span> <span class="pre">==</span> <span class="pre">true</span></tt> is and only if <tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a>&lt;s1&gt;::value</span> <span class="pre">==</span> <span class="pre"><a href="./size.html" class="identifier">size</a>&lt;s2&gt;::value</span></tt>
and for every iterator <tt class="literal"><span class="pre">i</span></tt> in [<tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a>&lt;s1&gt;::type</span></tt>, <tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a>&lt;s1&gt;::type</span></tt>) <tt class="literal"><span class="pre"><a href="./deref.html" class="identifier">deref</a>&lt;i&gt;::type</span></tt> is identical to</p>
<pre class="last literal-block">
<a href="./advance.html" class="identifier">advance</a>&lt; <a href="./begin.html" class="identifier">begin</a>&lt;s2&gt;::type, <a href="./distance.html" class="identifier">distance</a>&lt; <a href="./begin.html" class="identifier">begin</a>&lt;s1&gt;::type,i &gt;::type &gt;::type
</pre>
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<div class="section" id="id612">
<h3><a class="subsection-title" href="#complexity" name="complexity">Complexity</a></h3>
<p>Linear. At most <tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a>&lt;s1&gt;::value</span></tt> comparisons.</p>
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<div class="section" id="id613">
<h3><a class="subsection-title" href="#example" name="example">Example</a></h3>
<pre class="literal-block">
typedef <a href="./vector.html" class="identifier">vector</a>&lt;char,int,unsigned,long,unsigned long&gt; s1;
typedef <a href="./list.html" class="identifier">list</a>&lt;char,int,unsigned,long,unsigned long&gt; s2;

<a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( <a href="./equal.html" class="identifier">equal</a>&lt;s1,s2&gt; ));
</pre>
</div>
<div class="section" id="id614">
<h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3>
<p><a class="reference internal" href="./querying-algorithms.html">Querying Algorithms</a>, <a class="reference internal" href="./find.html">find</a>, <a class="reference internal" href="./find-if.html">find_if</a></p>
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